INFO: task syz-executor.0:1339 blocked for more than 140 seconds. Not tainted 4.19.121-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27904 1339 6468 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 chrdev_open+0x219/0x5c0 fs/char_dev.c:423 do_dentry_open+0x4a8/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x1031/0x4200 fs/namei.c:3537 do_filp_open+0x1a1/0x280 fs/namei.c:3567 do_sys_open+0x3c0/0x500 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 Code: 08 48 c7 44 24 10 09 00 00 00 e8 02 a1 fa ff 48 8b 44 24 18 48 8b 4c 24 30 48 83 c1 10 48 89 0c 24 48 89 44 24 08 48 c7 44 24 <10> 58 1f 00 00 e8 dd a0 fa ff 48 8b 44 24 18 48 89 44 24 40 48 8b RSP: 002b:00007f3e8d494c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f73e0 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a0 R14: 00000000004ca544 R15: 00007f3e8d4956d4 INFO: task syz-executor.4:1337 blocked for more than 140 seconds. Not tainted 4.19.121-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28160 1337 6827 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 chrdev_open+0x219/0x5c0 fs/char_dev.c:423 do_dentry_open+0x4a8/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x1031/0x4200 fs/namei.c:3537 do_filp_open+0x1a1/0x280 fs/namei.c:3567 do_sys_open+0x3c0/0x500 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 Code: 08 48 c7 44 24 10 09 00 00 00 e8 02 a1 fa ff 48 8b 44 24 18 48 8b 4c 24 30 48 83 c1 10 48 89 0c 24 48 89 44 24 08 48 c7 44 24 <10> 58 1f 00 00 e8 dd a0 fa ff 48 8b 44 24 18 48 89 44 24 40 48 8b RSP: 002b:00007f492d7f9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f73e0 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a0 R14: 00000000004ca544 R15: 00007f492d7fa6d4 INFO: task syz-executor.1:1342 blocked for more than 140 seconds. Not tainted 4.19.121-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D27680 1342 6587 0x80000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x896/0xf20 kernel/time/timer.c:1782 __down_common kernel/locking/semaphore.c:221 [inline] __down+0x176/0x2c0 kernel/locking/semaphore.c:238 down+0x57/0x80 kernel/locking/semaphore.c:62 console_lock+0x25/0x80 kernel/printk/printk.c:2244 do_con_write.part.0+0xa8/0x1db0 drivers/tty/vt/vt.c:2571 do_con_write drivers/tty/vt/vt.c:2566 [inline] con_write+0x41/0xe0 drivers/tty/vt/vt.c:3133 n_tty_write+0xa69/0x1080 drivers/tty/n_tty.c:2354 do_tty_write drivers/tty/tty_io.c:960 [inline] tty_write+0x452/0x790 drivers/tty/tty_io.c:1044 __vfs_write+0xf7/0x760 fs/read_write.c:485 __kernel_write+0x109/0x370 fs/read_write.c:506 write_pipe_buf+0x153/0x1e0 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x38f/0x7a0 fs/splice.c:627 splice_from_pipe+0xd9/0x140 fs/splice.c:662 default_file_splice_write+0x37/0x90 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] direct_splice_actor+0x115/0x160 fs/splice.c:1025 splice_direct_to_actor+0x33f/0x8d0 fs/splice.c:980 do_splice_direct+0x1a8/0x270 fs/splice.c:1068 do_sendfile+0x549/0xc10 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64 fs/read_write.c:1494 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 Code: 08 48 c7 44 24 10 09 00 00 00 e8 02 a1 fa ff 48 8b 44 24 18 48 8b 4c 24 30 48 83 c1 10 48 89 0c 24 48 89 44 24 08 48 c7 44 24 <10> 58 1f 00 00 e8 dd a0 fa ff 48 8b 44 24 18 48 89 44 24 40 48 8b RSP: 002b:00007f46b720ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000004fc2e0 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0800000080004103 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008dc R14: 00000000004cb816 R15: 00007f46b720f6d4 Showing all locks held in the system: 1 lock held by khungtaskd/1078: #0: 000000004b771c46 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440 1 lock held by in:imklog/6126: #0: 00000000d7cfad32 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767 3 locks held by syz-executor.5/1333: 1 lock held by syz-executor.0/1339: #0: 00000000acafcea2 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 1 lock held by syz-executor.4/1337: #0: 00000000acafcea2 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 4 locks held by syz-executor.1/1342: #0: 00000000e0cf9b9a (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000006b438739 (&tty->atomic_write_lock){+.+.}, at: tty_write_lock+0x1e/0x80 drivers/tty/tty_io.c:886 #2: 00000000ab8f0d42 (&tty->termios_rwsem){++++}, at: n_tty_write+0x1b2/0x1080 drivers/tty/n_tty.c:2314 #3: 0000000086d60c78 (&ldata->output_lock){+.+.}, at: n_tty_write+0xa2f/0x1080 drivers/tty/n_tty.c:2353 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1078 Comm: khungtaskd Not tainted 4.19.121-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x962/0xe40 kernel/hung_task.c:287 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 1333 Comm: syz-executor.5 Not tainted 4.19.121-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x22/0x50 kernel/kcov.c:101 Code: 00 00 e9 24 ec ff ff 90 48 8b 34 24 65 48 8b 04 25 40 ee 01 00 65 8b 15 1c 24 9a 7e 81 e2 00 01 1f 00 75 2b 8b 90 d8 12 00 00 <83> fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12 00 00 48 8b 11 48 RSP: 0018:ffff888091357200 EFLAGS: 00000246 RAX: ffff88809e28c440 RBX: 0000000000000000 RCX: ffffffff83778c15 RDX: 0000000000000002 RSI: ffffffff83778c49 RDI: 0000000000000005 RBP: 0000000000000000 R08: ffff88809e28c440 R09: 0000000000000040 R10: ffffed10432d6123 R11: ffff8882196b091f R12: 0000000000000028 R13: ffff8880000a0140 R14: 0000000000000000 R15: 00000000ffffffff FS: 00007fa256433700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f471b139740 CR3: 00000000a00bb000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bitfill_aligned drivers/video/fbdev/core/cfbfillrect.c:78 [inline] bitfill_aligned+0x199/0x200 drivers/video/fbdev/core/cfbfillrect.c:35 cfb_fillrect+0x418/0x7a0 drivers/video/fbdev/core/cfbfillrect.c:327 vga16fb_fillrect+0x68f/0x1960 drivers/video/fbdev/vga16fb.c:951 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x2d8/0x370 drivers/video/fbdev/core/fbcon.c:1342 fbcon_switch+0xe0f/0x1970 drivers/video/fbdev/core/fbcon.c:2324 redraw_screen+0x37d/0x870 drivers/tty/vt/vt.c:1010 fbcon_modechanged+0x5eb/0x8f0 drivers/video/fbdev/core/fbcon.c:2972 fbcon_event_notify+0x1b2/0x1d54 drivers/video/fbdev/core/fbcon.c:3347 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93 __blocking_notifier_call_chain kernel/notifier.c:317 [inline] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] blocking_notifier_call_chain kernel/notifier.c:328 [inline] blocking_notifier_call_chain+0x85/0xa0 kernel/notifier.c:325 fb_set_var+0xc39/0xe00 drivers/video/fbdev/core/fbmem.c:1042 do_fb_ioctl+0x450/0x9c0 drivers/video/fbdev/core/fbmem.c:1115 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1230 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa256432c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e4860 RCX: 000000000045c829 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002f2 R14: 00000000004c54c8 R15: 00007fa2564336d4